1. Technical Field
This invention relates generally to catheters adapted to be inserted into the cardiovascular system, and more particularly to a new and improved catheter construction providing better torque control.
2. Background Information
"Torque control" refers to the ability of a catheter to transmit twisting forces along its length, and satisfactory catheter performance often depends on this ability. It enables carefully controlled maneuvering within the cardiovascular system by skilled manipulation of the catheter at the proximal end. Thus, catheter torque control is of recognized significance and each detail of construction enhancing this attribute of corresponding importance.
Apart from torque control, however, the catheter must also exhibit flexibility and softness, these attributes helping to avoid trauma to the cardiovascular system when the catheter is introduced. However, the materials and constructions utilized in existing catheter designs for flexibility and softness often exhibit too little torque control. Instead of transmitting twisting forces as desired, the catheter deforms elastically, and this makes manipulation within the cardiovascular system more difficult. Although reinforced catheters exist, such as those utilizing a braided layer, these are more complex to fabricate and more costly.
Therefore, it is desirable to have a new and improved catheter that overcomes this concern--one combining flexibility and softness in a construction exhibiting improved torque control. In addition, it is desirable that this be accomplished in a catheter construction adapted to be conveniently and inexpensively fabricated.